Líder (30): Any pawn from your band within 30 cm from Don Pedro will be able to use its Incentive and Audacity values. You can only include a pawn with this Peculiarity for every 250 Maravedies in your band.

You forgot to alter the name of the Peculiarity (Líder)

Seasoned: If Don Pedro is attacked after it has already been activated during the same turn, it can be activated again and fight normally against its enemy, but it will automatically be the responding pawn in the fight; and won’t be able to engage or push back, even if he wins the clash. This pawn will continue activating itself and fighting provided that it is attacked by an enemy, no matter how many times it has used this Peculiarity.

You change between 'it' and 'he' here - so maybe for consistency "even if it wins the clash."

Skillful: Don Pedro can use Common and Real Dexterity Cards.

Strategist: When it’s your turn to activate Don Pedro, you will be able to transfer his activation to any pawn from your band within 20 cm from Don Pedro, even if it had been activated during the turn. Chosen pawn will automatically activate, and Don Pedro won’t be able to do so till next turn.

Should be "The chosen pawn..." and "till" should be "until"

Top Brass: If Don Pedro is eliminated, enemy band will get 2 extra Honour Points at the end of the Conflict. And if he’s alive at the end of the Conflict, your band will get 1 extra Honour Point.

Furthermore, all pawns from Don Pedro’s band will have to make an Audacity roll, with a -1 modifier, in the moment he’s eliminated, or flee to their deployment area.

"the enemy band will get..." In the second sentence, the "And" is not needed and you again refer to the model with "he". I would go with something like this for the whole rule:

"Top Brass: If Don Pedro is eliminated, the enemy band will get 2 extra Honour Points at the end of the Conflict. Furthermore, all pawns from Don Pedro’s band will have to make an Audacity roll, with a -1 modifier, the moment he’s eliminated, or flee to their deployment area.

If Don Pedro is alive at the end of the Conflict, your band will get 1 extra Honour Point."

Old Purples’ Ensign: All pawns from your band within 30 cm from Don Pedro, will be able to apply a +1 moddifier to any of their Audacity rolls.

"moddifier" -> "modifier", within uses 'of' as the correct preposition so "from" -> "of" and the "any of their" seems superfluous - could just be "to their Audacity rolls" or even "to Audacity rolls". Also, as far as I know, ensign refers mostly to naval flags so maybe just use banner or standard. So Old Purples' Banner.

“¡Desperta, Ferro!”: You can use this Peculiarity at any time, investing 1 Maravedi for every pawn in your band within 20 cm from Don Pedro that you want to be affected by this Peculiarity. If you want, you can even interrupt your opponent to do so. Pawns affected by this Peculiarity will be able to apply a +1 moddifier to their Attack and Reply rolls during the rest of the turn.

Again, change to "within 20 cm of Don Pedro" and "moddifier" -> "modifier". I would also change "during the rest of the turn" to "for the rest of the turn" but it should work either way.

Leader (30): Any pawn from your band within 30 cm from Degoyito will be able to use its Incentive and Audacity values. You can only include a pawn with this Peculiarity for every 250 Maravedies in your band.

"within 30cm of Degoyito"

Authoritarian: Degoyito cannot be engaged under any circumstance when charging.

I would change "when" to "by"

Crippled: Degoyito can only use “walk” and “charge” Movement Maneuvers, but the second one only if he charge to an enemy pawn for engaging him in a clash.

I would change the latter part of the sentence, so go with: "Crippled: Degoyito can only use “walk” and “charge” Movement Maneuvers, and the latter only when charging an enemy pawn to engage it in a clash."

Quarrelsome: Degoyito can use Common Dexterity Cards.

Martial Law: At the end of the Conflict, Degoyito’s band won’t loose Honour Points for killing Antagonists, nor pawns from the Rearguard.

"loose" -> "lose"

Furthermore, Degoyito’s band will get 1 extra Honour Point for every enemy pawn eliminated, that killed one of their partners first.

Enemy Prisoner: Enemy Prisoner must be deployed at same time as Degoyito, and in contact base to base with him. Prisoner must be ignored by enemy pawns, which won’t be able to engage him in clashes, attack him, nor choose him as target of Discharge Maneuvers or Blessings. This way, Degoyito’s base side occupied by Prisoner must be considered to be in contact to a scenery element.

"in contact base to base with him" -> "into base to base contact with him". Also, maybe add something like "When Degoyito moves, the Enemy Prisoner moves with him staying always in base to base contact." All cases of "him" -> "it". "choose him as target" -> "choose him as a target"

While Degoyito is with his Prisoner, he neither will be able to be taken as target of Discharge Maneuvers.

"he neither will be able to be taken as target of Discharge Meneuvers" -> "he can't be chosen as a target of Discharge Maneuvers".

“This is How I Treat the Criminals”: At the beginning of Degoyito’s activation, he can invest 1 Maravedi for torturing his Prisoner. During the rest of the turn, any pawn within 30 cm from Degoyito or his Prisoner will have to roll 2D10 for their Audacity rolls. Ally pawns can choose the result they prefer, but enemy pawns will have to choose the lower value.

Furthermore, once a Conflict, Degoyito can execute his Prisoner. This way, any enemy pawn within 30 cm from Degoyito or his Prisoner will have to make an Audacity roll. If they fail won’t be able to activate during the rest of the turn. Then, Prisoner must be placed out of the game surface, and Degoyito won’t be able to use this Peculiarity or “Enemy Prisoner” Peculiarity during the rest of the Conflict.

[i]I would go with "once per Conflict". within from -> within of. "If they fail won't be able to activate during the rest of the turn." -> "If a pawn fails this test, it won't be able to activate for the rest of the turn." "must be placed out of the game surface" -> "must be removed from the game"

Again, really cool stuff. I especially like how the latter part of Martial law creates an interesting dynamic to the whole match. Really nice!